Pleiotropy is when a gene has more than one phenotypic expression. There are plenty of examples, but I can’t think of any.

I assume you mean Epistasis. Epistasis is when one gene controls whether another is expressed or not. But it isn;t like dominance and recessive genes, where the dominant one trumps the recessive.

I can think that Epistasis is some kinda dominance that expressed when two or more alleles which controlling one phenotype (usually color phenotype) meet each other (when two organisms are mated). In this matter Epistasis can be detected when two dominant alleles meet each other but only one of them is shown as phenotype. In this case another allele which is ‘beaten’ by the Epistasis allele is called hipostasis.

These sites should help…

http://www.ndsu.nodak.edu/instruct/mccl … endel6.htm

http://www.ndsu.nodak.edu/instruct/mccl … endel5.htm

as my knowledge i have found that One gene that causes many different physical traits such as multiple disease symptoms.

go to http//www.yahoo.com and search for your help chances are you’ll get answers

Sickle-cell disease is a good example of pleiotrophy, the carrier of this recessive trait will have a phenotype of lets say Ss but they do not have Sickle-cell symptoms like the SS phenotype. However even in the Ss type some sickle-cells are created this is why they are resistant to malaria.